Hey there. Nice job man. I dont know much about guns but it looks pretty good to me. Im just noticing a few things...Is that whole model combined as single polymesh? Cuz im seeing a few things that can be fixed such as that boxy thingy which looks that it was just boolean'd and the top area aiming part (dont know what to call it) looks booleaned which both leaves trails of polys with more than 4 sides. Maybe you fixed it already. but yeah Good job!